Radioguy7268

I'd also be checking your antenna feedline for continuity. What you described with the ability to transmit, but not receive, could potentially be caused if you have a VERY slight gap between the coax and the connector - effectively creating your own iso-tee. That's why people ring out their connectors when they're done installing them. With your adapters on each end, that possibility becomes a bit more likely.

How did the other user have their radio set up to respond to you? Normal function on a repeater channel is that the portable would listen on 462.xxx, but transmit on 467.xxx If you go to Simplex, your portable is now transmitting and receiving on 462.xxx Unless the other user switched their radio to simplex also - they would still be transmitting on 467.xxx and of course your portable that's listening on 462.xxx would not hear them. As Sshannon mentioned above - there aren't many scenarios where an antenna line would be passing transmit, but blocking receive. I'd put money on the distant user still transmitting on the high side of the split at 467.xxx

You can try this one: 135K4414K073AWGG

There are companies that aggressively search for "open" areas lacking coverage that also have the ability to have a tower placed there. Those companies are responsible for 90%+ of all new tower site builds. They have lawyers at their disposal, zoning specialists, and years of experience building out sites. They also have relationships with wireless carriers, and know that they're likely going to have 1 or more carriers as tenants on the site before the first shovel hits the ground. That's the kind of business plan you should have before you go spending hundreds of thousands (or more) to put up a tower.

I would be curious to know what component of a notch duplexer failed. Unless something cracked or corroded, there's just not much to go wrong inside a tuned cavity.

It's nearly impossible to troubleshoot a system you've never seen from a thousand miles away, but please explain what you did to "tune the repeater closer to the correct freq." ?? There's not much tuning that I'm aware of with a Bridgecom repeater. Were you trying to bring the repeater closer to frequency center on transmit? Just how far had it drifted?? If the setup worked fine (repeater + duplexer) with one antenna system, and then you changed out to another antenna system - it would certainly seem that your new antenna system is suspect. However, I'm curious why you would have needed to "tune the repeater closer to the correct freq." if your range testing with the old antenna system was producing stellar results. What connectors are you using on the LMR400 cable? Was that cable new or used? How hard would it be to swap out the cable? What condition are the duplexer jumper cables in? Heliax is "better" than LMR400 - but for a 35-40 ft run, it should be marginal - especially when new. That Harvest antenna probably has an SO-239 UHF connector, and the DB404 would have had a Type N. Type N is "better" - but again it's not a night & day difference maker. What connections are on your duplexer? Do you have a surge protector or lightning arrestor in the mix? For all the internet stories about duplexers going bad just sitting there, I haven't really ever seen it in the real world. Unless an elephant stepped on it, Zeus hit it with a lightning bolt, or Mike's Magic Golden screwdriver tried to field tune it, then it just kept on working. What I have seen is cheap cables with tin plated connectors deteriorating within a few years and causing all kinds of headaches that get attributed to a bad duplexer.

The most simple way to troubleshoot a repeater is to start with the basics. If you can, follow OffroaderX's suggestion and set up a simplex mobile radio (or temporarily reprogram the repeater as a simplex base - disable the repeat function). Connect the "base" radio directly to the antenna - forget about the duplexer for now. Get a helper to take a radio out to the current 5 mile edge of the system range. Test the transmit function to a distant mobile. You should get the same range (assuming power level is the same as the repeater). If your range increases - need to look at the duplexer and cabling. Now test receive function from that distant mobile. You should be able to receive from a similar distance as you could transmit to. If your receive range improves from what you saw with the repeater - you need to take a look at the duplexer and cabling. I have seen more bad cables than I've seen bad duplexers. Your story about the system working well with the other previous antenna makes me wonder if you were using the same duplexer and cables for that setup. Have you measured VSWR for the antenna system? Do you have the ability to sweep the antenna? That Harvest antenna is tunable - was it set for GMRS when you ordered it? What frequency was it supposed to be set to? Don't just guess at what's wrong. Measure & test so that you know what is working and what seems to introduce trouble when you add it to the mix.

Look for a used Vertex, Kenwood, or Motorola commercial repeater. You could get something like an MTR2000 that's rated for 100% duty cycle at 100 watts (it will do 50 like a breeze) - and still spend less than trying to get 2 Wouxun mobiles strapped together. Most sellers will program and set up the repeater, and give it a warranty as well.

I think you might have meant to say "relegated" to the dustbin of history, but over regulation will get you to the same place

15 to 20 watts. Don't sweat, it will still be 3x better than a portable.

Yes, a genuine kit would include the cables with the correct orientation tabs. But, the really cheap $10 "repeater maker" cable kits sold on Ebay have no orientation tabs, and can be plugged in either way. I have also seen people totally jam in the correct cables upside down, because they were convinced that the tab orientation was incorrect - since it didn't match their old MaxTrac. They never even noticed that the M1225 dust cover has a diagram molded into it showing the correct orientation.

It's because GMRS licenses are tied to an individual, not to a location. You could be a GMRS License holder in one state, and then have a repeater located in another state, and the FCC would have no idea where your repeater is located. You could also be the License holder, and your sister who lives 2 states away could be the actual user, or her kids. There's sometimes little correlation between the License, the user, and the location with GMRS. If you do want to find out who your local GMRS peeps might be, then yeah just search for ZA within your town/zipcode. Please realize that many of the License names listed might not be actively using GMRS radios, and would probably rather NOT be contacted.

Full disclosure - I've never had a Retevis repeater on the bench to test it out. Judging by the price point (and the design of their portables) it's probably based on a simple Direct Conversion receiver, which are sensitive, but prone to overload. I'd agree that for a simple "quick and dirty" low elevation repeater, it probably does the job for a majority of users looking for their own specific solution. The Retevis is at least less than the cost of a good used MTR2000. I'd really ask anyone looking at a Bridgecom or building their own Woxoun repeater out of 2 mobiles to stop and check out the alternatives available. You really can end up with more for less, if you consider used Part 90 gear. And, that used Part 90 stuff has a resale value when you're done with it. Something you won't really see with used Bridgecom equipment.

Creating a repeater out of two radios that meet Part 95 does not mean you've got a Type Accepted Part 95 repeater. As mentioned, it is also quite expensive compared to the (IMHO better) alternatives. Vertex. Motorola. Kenwood. They all made good Part 90 repeaters. Some will put out at least 50 watts at a 100% duty cycle. Used units are available that will outperform a Bridgecom - and do it at a better price point. They also have a history of performance, along with available support (that you will probably never need).

Yup, no WiFi - no Bluetooth, and lacking GPS. 3 things that might be important if you built a fleet around advanced feature stuff like Indoor Location or Enhanced GPS. Those chips are also missing now in the XPR3500e/3300e portables. The good news is that by dropping those features, they reduced the lead time to months instead of years. A recent customer order for some XPR radios shows a January 2023 expected ship date. The good news is that by getting the order in now, I have already beat the next 2 expected price increases.

I laughed when I read that. The Gman does NOT spend big money on his radios. Most of his Motorola gear was acquired at prices well below dealer cost. I'd venture to say that every Moto radio he owns could be sold today at a profit. Not sure many CCR owners could say the same. But, you're right about receivers.

Make sure to terminate any un-used port on the combiner star if you remove the cable and/or isolator from use. I think you're going to find that one or more of the isolators you were using will no longer tune. Measured forward loss through any specific dual isolator when measured on its own should be less than 1 dB when properly tuned. EMR has a ton of white papers online concerning combiners/filters/isolators, antennas, and duplexers. Lots of good info there, even if I never liked their square cans. EMR Corp tech papers I'd suggest reading "The care & Feeding of the RF Isolator" on that link if you haven't already. It will set you straight with what's going on. EMR also did a writeup on how to Field Tune a Dual Isolator: Field Tuning a Dual Isolator

As everybody told you in the other forum, the spacing was too close. As for the cable length, yes you need to be fairly precise, and your measurements need to take the connector length into consideration. I can tell you that TX/RX Bird used to stock cables in 1/8" increments, and they would sell them to you at reasonably inflated pricing, but to me it was still cheaper than the time spent to make your own. Not sure if they still do that. There's a reason I know how close they'll go. I was down this road with VHF combiners 20 years back, trying to make existing stuff work at spacing under spec. Don't try to jam 100 watts into the combiner, don't expect miracles, and pay attention to the size of the dummy loads you're dumping the isolators into. You will need something rated for more than 5 or 10 watts.

Years back there was an interesting write up that a club did - where since they were going to have to sidemount their transmit antenna - they ended up going with a 3 sector antenna system using stacked 3dB yagi antennas, and used a phased harness to make it all work. At least, that's how I remember it, and now I can't find it online with a weak search attempt. I do remember that it was an interesting article, wish I could find it again.

Since you're still trying to do the impossible - it's not surprising that you're having trouble. Pretty good bet that 1 or more of the isolators is burned up. There's a max amount of reflected power that an isolator will handle. Think of what you're doing when you place another transmitter right next door on a frequency too close for the design spec. Think what happens once that 3rd transmitter keys up... it's adding to the problem, and it's not that much further away. Loss on a typical bandpass single cavity/dual isolator combiner setup should be 1.5 dB per channel.

If you've got a 5 port "star" (4 transmitters feeding into 1 antenna) - then the 4 harness legs coming from each tuned transmitter cavity would typically be an odd wavelength ( 1/4, 3/4) of the frequency you're using. I question the spacing you're using, as typically if you get that tight on frequency (less than 50 KHz) spacing with a combiner, you will need a hybrid/ferrite combiner - and 10 dB of loss is typical of those. 250 KHz would be more typical of the absolute minimum spacing for a bandpass cavity design with a dual stage isolator for each channel, not 25 KHz. http://www.repeater-builder.com/antenna/db/pdfs/db-about-combiners.pdf

For anyone planning to implement MDC signaling, you should investigate the use of DOS (Data Operated Squelch) and PTT Sidetone. I'd recommend only using it in a group if everyone on the repeater is using MDC, and everyone agrees on the setup parameters. If properly done, the users on the system will not hear the MDC squawk, and every radio on the system can ID other users. MDC can also be used for selective calling, radio alerts, and Status updates. It's a pain to set up if you're using multiple radio models across different manufacturers. DOS will silence the MDC turkey call noise (either pre, post, or both) for users that have it active - and a PTT sidetone can be useful to remind the user to pause for a moment until the MDC pre-burst is sent. Set the PTT sidetone to something less than obnoxious if you're using it. Whackers like MODAT, MDC and PTT Sidetone - even when they're not actually using MDC for any signaling benefit. They just think extra noises sound cool & they heard all those noises on their Bearcat Scanner - so they think that the radio users must be hearing those noises too. Well designed radio systems don't annoy their actual users with squawks and obnoxious beeps.

PL stands for "Private Line" - which was Motorola's term for ctcss (continuous tone coded signalling squelch). It's a sub-audible tone that's generally between 80 and 300 Hertz. It seems you have already figured out how to plug that in. DPL is Digital Private line - which most manufactures call DCS - Digital Coded Squelch. I'm not familiar with the Wouxun product line, but other people here are, and I'm sure someone will tell you how to plug that DPL code into your radio in order to access the repeater. If the repeater you are planning to use has PL on the one frequency, and DPL for the other (probably higher) frequency - that's termed a "split tone". Not all radios are capable of using split tones - but you might be in luck with the KG-935g.

A good "courtesy tone" is generated by the repeater, and should be at least 10-12 dB down in volume from the voice audio. In other words, the courtesy tone is well below the user's voice level. It should not be shrill or harsh. It's more of a clue than a control signal... A radio that generates its own Roger Beep upon release of the PTT should be avoided IMHO. I haven't played around with enough CCR's to know what's available in the programming, but the tones I have heard over the air on GMRS usually seem to be on the edge of obnoxious.

GMRS rules used to specifically mention that any Non-English conversations still needed to ID in English (or CWID). I'm not sure if the newer version of the rules still says that, but I can tell you that my family regularly uses non-English on the repeater, and allows the CWID to take care of identifying. I don't really care if A$$C10WN gets upset about that.